I see through your lies... there WAS no 9mm in Fallout 3.
You're right, it was a 10mm that was in the game, though in practice, I doubt a 9mm would have behaved any differently as far as gameplay is concerned.
That was very annoying, What is the point of getting a stealthy, hidden kill if everyone in the whole town would end up turning hostile towards you afterward?
Very much defeats the point of playing a stealth character in my opinion.
I have to agree there, they really need to improve NPC detection of a stealth-using character. Now, if people suddenly see someone die from a shot to the head, they should obviously get suspicious and start looking around the environment, but they should not psychically know it was you. They should only know you are the culprit if they actually see where the bullet came from.